full-read, full-write: relax license Jim Meyering gave consent to this action: http://lists.gnu.org/archive/html/bug-gnulib/2010-04/msg00446.html * modules/full-read (License): Drop to LGPLv2+. * modules/full-write (License): Likewise. * modules/safe-read (License): Likewise. * modules/safe-write (License): Likewise. Signed-off-by: Eric Blake <eblake@redhat.com>